I have some questions about FAR code

[Bournwog]

function FixedAspectRatio() {
    // optional fixed-dimension images (regardless of aspect ratio)
    if (!$this->far) {
        // do nothing
        return true;
    }
    if (!$this->w || !$this->h) {
        return false;
    }
    $this->thumbnail_width = $this->w;
    $this->thumbnail_height = $this->h;
    $this->is_alpha = true;
    if ($this->thumbnail_image_width >= $this->thumbnail_width) {
        $aspectratio = $this->thumbnail_image_height / $this->thumbnail_image_width;
        if ($this->w) {
            $this->thumbnail_image_height = round($this->thumbnail_image_width * $aspectratio);
            $this->thumbnail_height = ($this->h ? $this->h : $this->thumbnail_image_height);
        } elseif ($this->thumbnail_image_height < $this->thumbnail_height) {
            $this->thumbnail_image_height = $this->thumbnail_height;
            $this->thumbnail_image_width = round($this->thumbnail_image_height / $aspectratio);
        }
    } else {
        $aspectratio = $this->thumbnail_image_width / $this->thumbnail_image_height;
        if ($this->h) {
            $this->thumbnail_image_width = round($this->thumbnail_image_height * $aspectratio);
        } elseif ($this->thumbnail_image_width < $this->thumbnail_width) {
            $this->thumbnail_image_width = $this->thumbnail_width;
            $this->thumbnail_image_height = round($this->thumbnail_image_width / $aspectratio);
        }
    }
    return true;
}

this lines if w==0 or h==0 than exit. weight and height must be not zero

if (!$this->w || !$this->h) {
    return false;
}

but in this lines we check the same, we can't go next "elseif"

if ($this->w) {
if ($this->h) {